The only fundamental principle of neuroscience

August 19, 2013

The brain is complicated. Really complicated. You just won’t believe how vastly, hugely, mindbogglingly complicated it is. I mean, you may think that your laptop is a complex piece of engineering, but that’s just peanuts compared to the brain.

I mean, there are loads of different types of neurons, synapses, glial cells, neurotransmitters, receptors. Genetic, epigenetic influences. There’s even the cerebellum, whatever that is. These all interact at a range of spatial and temporal scales, from the microscopic to the macroscopic. Loops and networks. Top-down, bottom-up. And all of this complexity comes together to allow us to do the glorious, epic meaningful things we do: walk the dog, stare at passing traffic, allow a solitary tear to roll down our check, maybe even write a blog.

And in response to this complexity, what do we do? Well, we could give up and do something else (bee-keeping perhaps). But instead, we try to make sense of it all, and we do that by making it simpler. We look for underlying fundamental principles, capable of explaining big chunks of this complexity. And everyone agrees that this approach is a good, and a noble and a wholesome and a sensible thing to do.

As a result, the world is awash with fundamental principles. The bayesian brain, the small world brain, the homeostatic brain, the efficient brain, the critical brain, the computational brain, the dynamical brain, the hierarchical brain, the sensorimotor brain, the topological brain, free energy, fast and slow thinking (OK, we can’t think of any more, we should probably read more widely).

The NeuroRant wishes to point out, however, that while these different approaches have plenty of merit, there’s only one real fundamental principle out there: the brain is a hack. This fundamental principle trumps all the others. So we’ll say it again, the brain is a hack. We don’t mean that the brain is a hack as in teenagers in Guy Fawkes’ masks and irritating acronyms. We mean a hack as in: “an inelegant but effective solution to a computing problem” (to quote Wikipedia). No doubt, evolutionary processes followed many principles in shaping the brain, but in the end, the human brain is a jury-rigged, hatchet-job cobbled together out of bits of string and sticky tape. Therefore, any of these other (inferior) fundamental principles are going to turn out to be inadequate when enough data is put together.

So kids, be warned and keep frosty when you read those all-encompassing review articles; you know the ones we mean, the articles that seem to really tie all of the data together. A healthy dose of skepticism accompanied by pain and confusion is the only way to go.